What day of the week is any date?
Pick any date, past or future, and see which weekday it falls on plus its ISO week number. Useful for birthdays, historical dates and planning around week numbers.
Weekdays and week numbers, settled
Which weekday were you born on? Which day does your deadline actually hit next year? Questions like these are one lookup, yet people still count on their fingers across calendar pages. Enter the date and both answers appear at once: the weekday, and the ISO week the date belongs to.
The week number deserves the extra attention because half the world runs on it. In Norway, Sweden, Denmark and Germany, meetings are booked for "uke 45" as naturally as for a date, while most English-speaking countries never use the concept. If you work across that line, the week number here is the ISO 8601 definition everyone's calendar software agrees on: weeks start Monday, and week 1 contains the year's first Thursday.
Planning around a specific date? The workdays calculator counts the business days to it, and the holiday calendar shows which red days interrupt the count in Norway.
FAQ
How far back and forward does it work?
Any date the Gregorian calendar covers is fine, so birthdays, historical events and far-future planning all work. Dates before the Gregorian reform of 1582 use the proleptic calendar, which is the standard convention in software.
What is an ISO week number?
The week numbering defined by ISO 8601: weeks start on Monday, and week 1 is the week containing the year's first Thursday. It's the numbering used in Scandinavian and German business calendars.
Why do week numbers sometimes surprise people?
The turn of the year is the trap: 29 December can already sit in week 1 of the next year, and 2 January can still be week 52 or 53 of the old one. The Thursday rule decides it.